So here's my family's situation. I have a nice sort of entry-level Cannondale F5 26in. mountain bike that we purchased early last Fall. Cannondale had a bunch of petite/XS size from '09 just languishing in a warehouse, so they sold them off cheap and we got it for half of retail ($350, instead of $700).
The bike is really a size too small for me, but fits my 11 year old DS pretty well...by next Summer it should be a perfect fit. Last night we went riding on some easy single-track with me on the mountain bike and him on his CX bike. He was bombing around like it was nothing. There were a few spots where his CX bike was not well-suited, though, like sand and some roots. He and I would both like to be able to ride together more, even hitting some more challenging trails an hour-ish away.
So the logical next step would be to get me a larger, better bike that I can ride more indefinitely--or until he grows into it, then I would upgrade again to a 29er (because I ride for JDRF I am eligible for 20% off Cannondale bikes, plus that is our LBS's primary brand...but thus far Cdale does not have 29ers smaller than size M--we expect that to change in the next year or so if they want to remain competitive with every other major mfgr.).
Perfect plan, right? OK, here's where the wrench gets thrown into the works, thus messing everything up.
My baby (and I mean BABY...31 going on 13) sister has plans to get married in Vegas in Dec. as a sort of Mayan Calendar joke. So the money that COULD go towards another bike is instead being diverted to airfare. My folks can't even afford to see their DD get married, but my sister doesn't seem to give 2 hoots about that. Even her 2 young sons will not be at the wedding (at first she wanted them to be, but everyone talked her out of bringing 2 small boys--one of whom is quite autistic and easily overstimulated. Plus they'd have to pay for airfare for 4, instead of 2), nor her BFF.
I don't even want to go to Vegas...BTDT. We can't afford for my DH to join me, either. I'd SO much rather have a new bike and get to see my sister get married within driving distance (we live in MI, they live in WI)...see my folks, see my nephews, etc. She doesn't realize that by getting married in Vegas and having only a handful of guests that she will be missing out on a lot of fun (and gifts from a much broader group of friends. As it is we will be putting so much money into my participation for her wedding that THAT will be their gift from us. Christmas will be slim, too). Weddings are dumb.