im a mechanic an have done this to my car myself (no im not offering to do yours ...lol...)
I reckon $800 including a new water pump is a good price (your coolant flush was a bit of a waste when it'll all be drained out to change the water pump...but oh well), its about 4 hours labour for all of that so theres about $350-$400 there depending on labour rate itself. An parts would be about $400 as well id say
gates blue belts around $110-$130
tensioner & idler pulleys + new bolt around $130-$150
crank & cam seals around $30-$50
Water pump around $130-$150
few litres of coolant & bleeding up your cooling system around $50 - $70 (depends on what brand/type used)
so going on the higher side of my guesstamation.....theres $550 right there without the labour of changing it all, if they have a cheap labour rate of around the $350 for the 4 hours. Theres you $800 right there, which is a good price if you ask me, go with it.
hope thats of some help. Cheers