To be honest, you are both pillocks.
You sound moany and whiny cos he didn't spend enough on your engagement ring, and he is a pillock coz he is being a typical MAN and spending family money on his frankly quite expensive hobby! No-one needs 9 fucking guitars, and I am willing to bet that no man - including the OP's man, would tolerate his woman spending several 1000's on her hobby.
Some men seem to think they're entitled to spend more on their hobbies though, if they earn more money.
Honestly, every third woman I know has a husband or boyfriend who spends fuckloads - I mean multiple 1000's on any one or more of the following....... Snowboards, ski-iing, golf, football, cars, gambling on the horses or the dogs, sci-fi collectibles, fishing, the gym, cycling, fancy sports-wear, tech, activities with his mates like paintball, or climbing etc etc. I have yet to meet a woman who spend a FIFTH of the money on her hobbies that her husband spends on his.
And despite what a pp said, it's not HIS MONEY. It's family money. They are getting married, and have a baby already. It's FAMILY MONEY.