I left a previous employer to pursue a contract that was more in line with my passions. When I left, they told me I could come back at any time. Now, the contract has run out and I'm looking for a full-time job again. I'd like to ask them if I can use them as a reference and I'd also like to ask them what they would pay if I went back to work for them, since I'm now several years more experienced.
Is it inappropriate to ask a previous employer what they'd pay if I returned to them? If not, what is the most polite way to ask that?
If not, would it be inappropriate to ask for both what they'd pay and for a reference?