Without discussing other tack systems, sticking to traditional tubular you have more options now that for quite some time. Menards track offers a large selection of curves now with brand new prices less than used track in other brands. There may be some issues with loose pin connections that will require squeezing with pliers. I believe Menards offers O31,O36, O42, O54, O72 and O96. single pieces run $3-$4 each, and in cases of 24 they drop to $2-$2.50 a piece. 30 inch straights are also 5 bucks each, or less than 3 bucks in a case.
When it comes to switches, I'll agree that Ross probably makes the best switch. They are a little pricey, but offer tubular switches that will mate up directly with your tubular track. Another option may be to use Fast track switches with the adaptor pieces to switch back to tubular track, if you will have only a few switches and large area's of the layout without switches.
JGL
