cheapest way to go from 2" lift to 3"?

Yup, just do the top plate spacers that so many ppl do to add to your current setup. For the rear just add a 1 inch block and there you have your cheapest way to get this little boost. If you don't already have shims to correct pinion angle look to something around 3 degrees to use with adding the blocks, or a tapered block if there are any around that fit the 1 inch lift.. The small top plate spacer with your lift is still a better solution than guys running top plate spacers for their 3 inch lifts.

 

now that I think about it
another way might even be to swap the old spring out and put in a new taller one. There's lots to pick from. Taller OME ones. Toytec. etc
And then only adding blocks to rear AAL.

Did not know shims are needed for rear lift block spacers, I will look into those thank you

currently only spacer is a 1/4" (translates into 1/2" real world) metal one ($30?) on one side of the front to fix the infamous "Taco Lean" that I think might be sandwiched between the coil; I forget. IIRC those are installed between the coil and top plate (require spring compressor) whereas spacers work like an adapter where they get bolted on top without compressing the spring (but top hat gets unbolted from truck to install them)

maybe these 1" blocks will get the rear up from 2" to 3"
but if 1/2" nets 1" then maybe they're relied upon for primary lift for people going spacer-only without AAL and I might need to shave them in half down to 1/2" (equals 1" in real life?)
will need to find new center bolts since I cut mine to fit the bumpstop back on and now it will have to be longer

I'll have to research front and spacer vs taller spring
looks like the only spacers ToyTec sells people rely on for spacer-only lift so they're all 2", 2.5", 3" metal. Not 0.5-1".
Headstrong Offroad appears to have it but sold out.
So if they're sold out then swapping a taller spring might be better because I doubt springs are sold out now. Or changing Bilstein 5100 notch to higher then seeing how much rougher it rides

 

The shims needs vary truck to truck, i always used them.. when I had an AAL I had shims and when I had the OME full leaf pack, it is not a spacer thing but just an overall lift height thing. and yes, a spring made to carry the weight of your bumper and provide more lift is a good plan also. just keep in mind that this will contribute to your current suspension topping out frequently if not a good match. Like are the 5100's strong enough to work well with heavier OME spring sorta thing.... didn't see your complete post at 1st...

the front is double yield from the spacers but the rear spacer will give the exact height the spacer is.

 

1 inch body lift