Day 147: Good Deal, Bad Deal

My craigslist ad is online since 4 weeks and I haven´t sold or traded the soundsystem yet. The price of 165$ is apparently too high, so I am now going to lower it every week for about 10$ until somebody buys it or until it becomes profitable to sell it on ebay (at around 125$).
I received a lot of interesting emails from people whowanted would like to trade some of their belongings for my soundsystem. Often it was easy to see that it would not be a profitable deal for me, but several times I was nearly at the point to make the deal. I am still convinced that bartering is a great method to make a profit, but I need definetily a better sense of what is  valuable/ marketable and what is not.
I listed all the noteworthy offers below, with pictures, if I received any. Below the description I explain, why I decided to deny the offer in the end. Would you have done the same?

Yamaha RGS 121 E-guitar + AMP
A student offered me this yamaha electric guitar with new "jazz strings", cable, a small amp, a tuner and custom strap. The model number for the guitar is RGS 121, I did not find any detailed information about the other things.
guitar ampYamaha RGS 121Yamaha RGS 121 

ME: I nearly accepted this deal. The problem for me was: I was only able to figure out the value for the guitar, which was between 66 and 120$.
I checked ebay and found some auctions that did not really give me any confidence:
The other things, such as the amp seem worthless or at least terrible hard to sell/trade. I expected that the price for the e guitar + amp etc. would be around 150$, maybe lower, but not higher.
In the end I decided to ask in a forum for advice and received responses that described the deal as "not a big loss to me". ..I wanted to make some profit with it..   So.. I did not take the e-guitar.

Toshiba 5205-S705
The person who offered this one said, it " has the blue screen of death (I think it just needs new memory), but if you are good with computers it is a good deal, its in very good condition other than the blue screen. It is definitely worth more than 165 even with the memory issue, but I don't feel like figuring it out."
Toshiba 5205 notebook

 (picture was not included)

ME: This was an easy one. The laptop is now 7 to 8 years old and is known for having a high component failure rate. It is definetily not worth anything close to 165$, I wonder if it is worth anything at all with the blue screen.

Fishtank with stand
A 55 Gallon (210 liter) fishtank with wooden stand and some basic supplies (shingles). A very similar fishtank is being offered on craigslist for 350$ in used condition.  The stand is made out of real wood (not plywood).
55 gallon fishtank and stand55 gallon fishtank and stand

ME: This was the toughest decision. I always liked to have a fishtank and the size and price was reasonable. However, the one for 350$ on craigslist had a more recent design and looked more attractive to me. I guess I would also have kept the fishtank.
55 gallon fishtank and standI finally did not take it, because I decided that if I am already trading the soundsystem for something, it must be something I can and want to retrade afterwards. The fishtank above has some serious disadvantages to the one on craigslist (the one below). The one below is much more stylish and has a black lid. I have the feeling (and that might be totally wrong) that the one above is very hard to resell, as it looks rather old. If the guy would have offered me the one below (which is the same model with different design),  I would have taken it, as the design is much "fresher". The fishtank on craigslist is online for many weeks already.  I finally denied the deal because I expected that I would not be able to sell or trade the fishtank for anything including the stand.  I am still not sure whether this was a good decision, some people might think that the fishtank stand is looking great. What do you think about this? Should I have taken it?

Fender CD-60 Dreadnought Acoustic Guitar
The most recent offer was a used accoustic guitar. Its new price is 199$, I could not find any price for it in used condition.
Dreadnought Acoustic Guitar (picture was not included)

ME: I do not see an chance to resell the guitar. I was able to find several guitars on craigslist, but the prices where not close to the prices in new condition. I could have sold it on ebay for about 140$, but it would not have been a good deal after ebay fees.

I am really curious whether you would have traded the soundsystem to any of the objects above. I am not sure whether I am too picky and might have missed some good chances.