I don't know when is was changed last , but $23 is a small price to pay considering this could put you on the side of the road waiting for a tow truck .
I work on a lot of old junk and no matter if its a bicycle , motorcycle , diesel truck or a toilet - maintenance is cheaper than a repair !
This stuff ain't that hard - if you don't know how to do it - look it up online !! If you still feel it's still beyond you , support a local shop and your ride will support you .
Stop spending hard earned money on something new and take care of the stuff you have . I find lots of good stuff at the dump simply because people do not take a few minutes to learn to fix a problem . You will feel rewarded with some new knowledge and working with your hands as well as have a few extra bucks for some beer.....