It's a free economy, you have every right to accept a job offer and spend your money how you want to. I wouldn't let anyone make you feel bad for buying an amp, if anything, I would lie to ppl that asked me "so, what are you going to do with your money from your job, they are fishing for info and I'd lie to them". Just my $.02... you sound like a decent person, and please take this as just my advice because I worked a part time job for 9 months to buy a Marshall half stack when I was 16, so it's like deja vu to hear your story here at the forum.
Good luck sir in your gear conquest!!