Any ideas on how to Terrace this hill without breaking the bank?

Actually think about edging the outer area and mulching with maybe some evergreen small bushes. It would be way more reasonable than the cost of a wall. You could even use stones for the edging if you have access to them.

cross ties are the least expensive

Hmmm, that looks like part of my back yard. I have a steep slope where I am in the process of killing off all the grasses and weeds. That's taking months as I want as few weeds as possible growing back. I have applied weed killer a couple of times and will have to do it at least one more time.

I am not terracing the slope, but will make steps from railroad ties as I'm too old to do all that work.

I am thinking of planting a low growing, spreading evergreen type shrub (somewhat expensive) or a vining Vinca that is less expensive. People plant ivy, but I think it can look messy as it gets older. I also have been looking at the planting on the banks on the sides of freeways to get ideas and may do something like that instead.

I bought tons of stone at a local quarry. They weigh your vehicle on entry and exit. I think it was 4 dollars a ton. Cheap and sturdy for a tiered wall.

Try finding some shale rock or someone who is ripping out an old slate patio... remove the grass, lay the flat stones you collected abd then plant pretty ground covers in the cracks? Anyway... just a thought

Ours didn't advertise it. I just walked into the office and asked

As someone who has a similiar issue in their yard, I just wanted ot compliment you on your grass condition. Its looks great even through it's probably hard to mow.

I've got creeping phlox on mine & it's 90% done taking over as I couldn't get grass seed to germinate well when we first moved in.

In a shadier part of my yard I did Bugleweed instead & it's looking good while helping with erosion & such.

The low growing evergreen bushes mentioned by others sound like a good idea to me. You could also do like barberry bushes in different colors &/or red or yellow twig dog wood bushes.

Use the plastic to cover the area and add you topping : rocks, sand, or dirt to start your new planting. Weed killer will continue to kill for some time and it will kill what you plant. It is safer to use the plastic.

There are a lot of ideas on YouTube. No idea how budget-friendly they are.

https://www.youtube.com/results?search_query=how+to+terrace+a+slope