Ask HN: Should I sell my side project?

Hello Everyone,

I'm currently in a very bad situation and I'm not sure what to do. I thought maybe someone could help me find a solution.

About two months ago I got in touch with someone who wanted to pay me about 5 grands to develop a software client which gathers ingame statistics of a game called "League of Legends" and eventually hire me later for developing a website to present some of those statistics. ( there was no payment in advance )

After working about 4 weeks fulltime, almost around the clock, I finally developed a client which does all the magic the customer asked for.

Well the client was working but the customer wasn't a programmer, therefore he paid only half of it and wanted an additional evalutation period ( about 2 weeks ) just to be sure everything works fine.

4 weeks later he still didn't payed the rest and I really got pissed off ( you know I really had to pay my bills and worked very hard to develop the client at a low price )

With those anger feelings I started to build my own statistics site ( www.lolstatistics.com ), it went Ok the first days but really took off within last 3 days. ( from 5k to 80k pageviews per day )

Okay now to my problems.

The guy who asked me to develop the software client responded finally

I showed him the website ( which just had 5k views at that time ) and he finally agreed to buy the site for 6 grands ( splitted into 3 rounds ) and pay the rest of the client

Now my pain is. I still haven't seen any money yet and he's already spamming on boards and communities to get "more" visitors. I didn't gave him the site yet and he's already starting to ruin the sites reputation.

I also realized that I probably sold my first real successful site, underpriced

I worked hard on it, bootstrapped it out of nothing, I created the client, designed the website, did the marketing and took and still take all the risk ( as the site may be shut down by the vendor of the game )

A platform architect from the vendor recently sended me also a email and wrote "I recently dropped by your awesome new site and it certainly looks great" and he wanted to talk with me with me.

So what should I do ?

Should I cancel the deal with the customer and take the risk to keep the site running on my own ( I still need to pay my bills ) or should I sell it and take the money for the website and maybe also some maintenance work ?

And what about the risk that Riot Games ( the vendor ) could take legal actions ?

Can someone give me an advice please ?