Yeah, Avatax prices are crazy for a small operation. I'm in a similar boat and ended up using a combo of manual setup and a cheaper API-based service. I use TaxCloud, it's not super flashy but it's way more affordable and handles multi-state rates decently. No native Abantecart integration either, but their API isn't too bad if you're comfortable setting it up or can get someone to help.

And yeah, your accountant's right, once you hit nexus in other states (economic or physical), you’re supposed to collect there too. It’s a pain, but ignoring it can come back to bite later. Keep it lean early on, but set yourself up to scale without headaches.

It's definitely more customizable than Shopify,  but the learning curve is steeper.  PrestaShop is somewhere in between, easier to learn than AbanteCart, but less flexible.  Cost-wise, AbanteCart is a one-time fee, so it can be cheaper in the long run if you're serious about building a business.

AI-powered product recommendations on the front end would be killer. Imagine suggesting related items or things customers who bought this also bought. On the backend, an AI chatbot for customer service inquiries could save a ton of time. Maybe even AI-driven inventory management to predict demand and prevent stockouts?