I did RightStart Level A with my 4 year old. It was a total success. We took it very slow... maybe 2-3 lessons per week, plus playing games. It worked really well for us as there wasn't a lot of writing. I just purchased Level B, and if money is tight, many Moms buy B and then drag it out for two years. I don't regret buying A though.

I loved the variety of manipulatives... tally sticks (a.k.a. popsicle sticks), colored square tiles, abacus, various cards showing both finger counting (hands), dots, tally sticks, etc. It really worked well for both DS1 and DS2.
I liked Singapore as well, but at the time DS1 just wasn't ready for worksheets as he didn't have the finger strength for writing. It is much cheaper, though.
(Oh, and yes, Saxon is the repetitive one.

They're now in public school and doing Saxon. )