My step mother came into our family about 5 years ago. My dad was widowed before this (not my mother).
Before she came along, myself and my brother would get token presents for our dad for Father's Day, birthdays etc. Normally spending no more than £20. I would make sure it was something nice that he would use but see no point in spending money that I can't afford on him when he is substantially better off than us.
I have a very large family and buy for about 45 people at Christmas and for birthdays so have to be careful with the amounts we spend.
The last three years or so, we have been getting a text about a month before suggesting presents to buy for our dad. They range from a new mountain bike to aftershave costing £80. Never anything below the £80 mark. I never comply with her suggestions and just do my own thing but I'm getting sick of her not getting the hint that we choose our own gifts. My dad was never bothered about receiving expensive gifts from us before so I don't think it's coming from him. I just wish she'd get the hint!
Dad is the type to buy himself whatever he wants and is not short of cash at all. He is aware I'm on maternity leave at the moment and have other financial commitments such as paying off the thousands we have spent on IVF the last couple of years.