Basic rule - if you buy to develop, the name on it's own really needs to be worth at least $1K depending on how you value your time unless:
1) It's a name that suits a project which is going to go ahead anyway or;
2) It's part of a niche you already are invested in rather than a standalone project
2) You have a mass low-cost development model that actually works!
All too easy to overcapitalise.