My first mold was a single cavity Lee .452" 252 SWC, bought in 1974. Still have it, although I've moved up(?) to double and four cavity molds. It has cast thousands of bullets and is nowhere near worn out.
Lee molds are aluminum and I think a beginner stands a better chance of casting good bullets sooner with aluminum molds. A double cavity Lee mold is about $20, with handles. You can't go wrong.
Yeah, wearing them out ain't gonna happen with NORMAL use. Beat them to death when you are using them and they won't last the week!
I started out with a TL230gr .452 RN 2 cavity Lee. I am going to be brutally honest here. If those were the only moulds available, I would stop casting immediately. It did function but was a pain to use. Mostly in the alignment pin area but also in the sprue plate.
In my opinion, the Lee 2 cavity moulds, even @ $20 aren't worth the money. Now, let me qualify that by saying the Lee 6 cavity moulds are. They need to have handles purchased too and are usually in the $40 neighborhood by themselves, but the alignment pins and sprue setup are TONS better. Not only that but you get 3 times as many bullets in each cast. Win/Win in my book.
I too have some mp-moulds.com moulds. They are top of the line. Guess what, as he was starting out, he copied the Lee almost to a tee only with improvements. They are well worth the money spent on them, in my opinion.
There are other options and none better than the out of production moulds from Hensley & Gibbs. If you want to measure mould performance/quality, these moulds are what folks compare other too. Hands down!
I own several of them, 9mm, 38, 45 calibers and nothing casts like a H&G, nothing.
Get ready to shell out some real dough for one though. An H&G #503, 4 cavity mould I had for a while cost me over $200 used! I was trying to cast for a Marlin 1894 rifle and couldn't get it to cast big enough. I decided to sell it. Made a bit on it and used it for several years. Their value does not diminish.
You can find them on ebay from time to time. Now though, anything I can get from an old H&G, I can get from an mp mould.
One neat thing that Miha does is the Cramer style hollow point moulds though. They are a really slick system for casting either solids or hp's.
FWIW