I'm trying to start up an art shop and I was hoping for some help with deciding what tier I would be

https://lensdump.com/i/tL1efm

I feel pretty confident changing colors and adding elements, but I always think my grounding could use more work.

I'd say Tier 2, start at 60-70k and increase the prices if you're finding your slots always fill up quickly.

I'd agree that your colour changes and roan and your manes and tails are really awesome, but there's also a couple things that need work like definitely grounding, as well as adding in a bit more definition to the form of the horse with shadow, especially in the second one.

Second this ^^ Beautiful work!

Thank you both! I appreciate it ^^

I'd say high Tier 3 or low Tier 2. You're decent at hair, and your grounding is very good, but your overall coat and body prep skills could use work.

personally I'd put you in High T3.

I like your manes and tails, they're solid and well drawn.
but what I think makes the piece lack slightly is the body prep. Definitely take a look at a few T2/T1 artists and how they add shadows to the horses body to define muscles, make the horse match the background with lighting and colour balance etc.
Then there's the ground! Shadows. To me it looks as though the horses and kinda floating. Just add the tiniest bit of black (with an airbrush) where the horse meets the ground, play with the opacity and it'll add that bit more realism to the piece.
If you find that you're getting lots of orders, up your prices!

Other than that, I think these are solid pieces! and if you need any help via art, I have a few tutorials that are hiding :P