Advice on slow payments?

[almondxjoy.livejournal.com]

So I'm looking for a bit of advice.

A user on FA was interested in buying a set of characters from me for the price of $226. 

I received the first payment of $26 the day they approached me (May 5th), and another $30 a few weeks later (May 24th) after I sent them a note asking if they were still interested. 

They've been posting journals frequently and I think they're still buying art (not entirely sure, but I do see stuff popping up with their name attached to it) so I'm not really sure if I should approach them again or not. 

At the moment they still owe $170. I'm not expecting the entire amount at once, of course, but a little contact would be nice since it's been almost a month since I heard from them.

I guess I'm just wondering if I should continue to be patient or send them another note asking if they're still interested.