It can certainly be scaled up, there are lots of models of 5 kwh lithium iron phosphate battery packs in server form factor for ~$1500-2000, 6 of those in a server rack and you have 30 kwh for ~$10k.
And is made to work well with this kind of inverter: https://signaturesolar.com/eg4-6-5k-off-grid-inverter-6500ex...
(They have a smaller 3 kw inverter for about half the price)
Also watch Will prowse on YouTube.
Here's a nice overview of setting up a 30 kwh battery and inverters to charge/use them: https://www.mobile-solarpower.com/48v-complete-system-bluepr...