Just to clarify, my windows are single hung with one vertical sliding sash windows not awning. They are in many homes in the Austin Area, made by
Alenco || Alenco in Bryan, TX.
They list 5 different dealers in the Austin area so you might be able to get competitive bids if you like.
I have seen similar windows for sale at Home Depot.
I replaced two 28x70 single hung windows and one arched glass window, all insulated glass with internal divided lites for $985.97.
Included in that cost was the round top arched glass $329 and installation for all of them at $195.