Okay your wife says that she will have sex with you but she doesn't enjoy it and you feel bad about that...you both have some things you need to talk about. You need to figure out why she doesn't enjoy sex and you need to figure out why you have such a preoccupation with masturbation.
I'm not saying there is anything wrong with masturbation...its normal....but an 800.00 toy. I mean it just isn't worth it to me...I bet you could talk your wife into do some pretty interesting stuff for a lot less than that...I'm sure she has her eye on some shoes or jewelry....she'd know what to spend the money on and you'd be havin sex.
I really think you need to talk to her about it...I mean I don't wanta get to personal and you don't have to answer but is she having an orgasm?
And honestly the porn thing isn't that weird I don't guess to me, I dated a girl who collected porn and probably had that much...she was a lot of fun...kinda crazy...but a lot of fun.