I think $200 is probably the ceiling on a mass market big ticket item for a line like SW. Could be wrong. Every 'big' vehicle they've done going back to the Naboo Royal Cruiser has seen some markdown and in many cases, steep ones. I got the BMF on clearance at Target; I got the AT-TE for $15 from TRU.
At $300 this is veering into Hot Toys / Sideshow levels of money and while I love those, they're cost prohibitive. When I spend $$$ on SW, it's on vintage toys and rarely. For some collectors this will be an easy sell, and for others not really. If it succeeds, and it may, then it probably heralds an increasingly interactive and expensive range of toys in the future. Imagine an app influenced X-Wing that opens and closes its wings. These things are cool. These things cost a lot of money.
There's been a stratification in the toy market for awhile now, as costs go up. You have a big push to make them affordable and accessible, while at the same time maintain some fidelity and integrity to the standards collectors have come to expect. It's why we have a 5 POA line at $7 and a SA one at $13. You could say that's catering to different audiences, or different wallet sizes. Long term, I don't know that's a good thing for a brand that's primary goal is mass market appeal. A casual buyer will never go for a $13 figure when a $7 one is available right beside it; consequently, there will never be the audience to support the $13 line in the way that a lot of collectors would probably see as necessary for it to be successful. Rounding back to the AT-ACT, I think that's ultimately where this thing falls. It won't work for the causal buyer, but will for a large enough core base to (maybe) justify it.