Well, since you've already tried the hockey skates and you did fine in them then maybe hockey skates are fine for you.
I think the reason that figure skates are recommended at first (and maybe just for little kids) is that the toe picks on the front of the figure skate blade actually stop you from falling flat on your face the first time you get on the ice - the blade flatter as well, which helps.
So you have to decide if all you want to do is skate backwards and forwards, because really this is all you can do in hockey skates. If that is your goal (which is great, by the way!) then stick with the hockey skates!
But if you want to learn to skate, do turns, learn freestyle, ice-dance, etc., then you really do need to eventually get some figure skates!
It is an expensive sport but as a beginning skater I think you don't need to spend THAT much. I have no idea how much hockey skates are but if you are actually thinking about playing hockey I know that gets expensive with all of the sticks and other gear that are required.
Once you have your (figure) skates there is very little else that is required - it may be a big expenditure at first but once you have the equipment then that is it. Then you just need to pay for ice time... and lessons... etc.
Have fun - skating is a great and lifelong sport!