I suspect you will find that reputable places who are selling online are very much prioritising their existing loyal customer base. Both of the suppliers I use are officially closed to new business, but are supplying people they know. Not sure what you mean by affordable, but with hardwoods you tend to get what you pay for. You will not be able to visit yards to select, so a relationship with a supplier you know will not send you junk is important currently.
Wickes are still selling on-line and delivering. They do have some packs of redwood though I would personally avoid the white softwoods unless it is for partitioning.
Might help if you tell is where you are and what sort of quantity you are looking for / what you intend to make.
I am looking basically for a few 1x8's for some smaller projects. Redwood is definitely something I like. I will check Wickes. Otherwise, I am in Watford. One local timber yard I tried today say they are closed for business, another one is only dealing with existing orders.