Hey @FearlessF
You don’t need to add the low/high price, that’s misinformation. Structured data done right (as mentioned above) will include all your variants including their pricing, URL, SKUs, GTINs etc which is what’s needed for Merchant Center.
If you contact me at support@ilanadavis.com and provide your website URL, I can do a free structured data audit to see if my app JSON-LD for SEO will help you. There’s no code needed. No setup involved. And we keep the data updated for you so that when Google makes updates, it just works.