Dewalt did make an add-on that would hold the arm up (
Dewalt Support arm) that really makes a lot of difference. You can also rig something up using a bungie cord, yourself, too. (
An example). Again - it will come down to how many inside cuts you will need to make. Funny thing is - once you use a good saw, you will tackle more projects with those cuts, and the ease of swapping blades will become more of an issue.
And again, all things being equal, should you be able to squeeze a DW-788 out of your budget, that is what I would heartily recommend. But if you can't at this time, start budgeting to get one or something of comparable quality.
For what it is worth, Amazon has them listed:
Amazon Dewalt DW788 as does the Grizzley site (
here)