You might be able to use one of these.
Check first, before you buy, to ensure it's compatible with your tongue jack.
I have the taller one. There are stops inside a few inches below the top (you can see the depressions in the picture) to prevent the tongue jack post from going all the way to the bottom.
I don't recall the exact amount of increase in height you get, but I think the total length is about 9" with a 6" increase in height.
It's a lot less expensive than the Fastway. I've had mine about as long as I've had my TT which will be 15 years in January.
Even with the extension/foot, I also still put a 2" x 4" and an 8" x 8" under the foot. Jayco put its TTs with slideouts on double-stacked frames back then which made them 9" higher than their non-slideout counterparts.