I would advise you to scrimp on any cost you can, except the moulds. The best "bargain" I know of are new RCBS and SAECO moulds, but they still will run you around $50 for a 2 cavity. Ebay is a good place to pick up used Lyman moulds, just make sure you know what you are getting. The older Lyman samples that I have seem to be of substantially better quality than the current 4 cavities I have from them. If you want to try Lee moulds, you may be completely satisfied. This is more likely if you don't use any other mould before you try the Lee models. Some people use them with great success, but I've had mixed results with them. I would encourage you to purchase a quality mould first and experiment with the Lee product on your second caliber. This way you will know how things should work to start with, it will help you to realize if you have gotten a bad mould when using the Lee's. The price is very tempting.
Jacks advise on a thermometer is very good advice indeed. Keeping your alloy at a temperature that works well with your mould is one of the bigget ways to increase the quality of your bullets and reduce the frustration that can be involved with casting. The .40 pistol will likely produce the best results right off the bat, as handguns don't demand the precision of a rifle, and alloy and lube seldom are a concern in comparison. Since you probably burn a lot more .40 ammo than the other 2, this would be the logical place to start. Now I'm going to contadict myself on the Lee mould issue. If I where to start with the .40, I might buy a Lee tumble lube design mould to get my feet wet. These moulds require no sizing or lube tools to make shootable bullets, so they may be a good starting point when on a tight budget.
Lee casting pots are a true bargain if they are withing your budget, but you'll still need the thermometer no matter what route you go. Another bargain, as far as sizing goes, are the Lee push-through sizing dies that you use with you existing reloading press. They are very simple, quite inexpensive, and use nose first sizing, which I beleive to be the superior method.
If you've got some wheelweights, heat source, casting pot, dipper, Lee liquid allox lube, and a Lee tumble lube mould, you'll be casting shootable bullets. You might want to splurge on a commercial fluxing agent, such as Marvelux, to clean your metal with. Make sure you read and understand the instructions with Marvelux if you go that route. The whole process, especially if you're using a dipper, is made much easier with clean metal.