Personally I would hate to work out at home. I like going out and being around other people, even if they are idiots at the gym. But I definitely agree with Bob in the sense that if you are going to be serious about weight training, bodybuilding, whatever, you need to have the right tools. And the only way to do this in your case, so it seems, would be to have a home gym. If your gym does have dumbbells then you could probably have some sort of mix where you work out at home and at the gym. That way you'd really only a need a squat rack and maybe an adjustable bench that goes from decline or flat to completely upright. What can't you do with those two pieces of equipment? Maybe this is entirely out of the question for you for a number of reasons, in which case I would say that I am very happy to not live in the UK.

Hopefully you're open to this, it probably would set you back under a grand. I don't know though i've never looked into buying equipment.