Welcome to the cost of owning a timing chain motor. You may be able to find a bit cheaper place on the labor, but you're still probably talking around the $1500~2000 range with an independent shop (you didn't say whether or not the cover itself is being quoted in the price, I assume it isn't since I think the dealership wants something like $800 for just the cover portion.) The front timing cover on a Timing Chain engine is more labor intensive than a timing belt motor and typically reflects that with a higher labor cost (though a comparatively lower amount of times it should/needs to be resealed/serviced when compared to a timing belt motor.)
You're basically removing the oil pan, the front of the engine, all associated components, then reassembling, and resealing all that back up. This means an oil change, coolant flush, probably a water pump wouldn't be a bad option since its coming off anyways, FIPG (Form In Place Gasket) for sealing, checking the components under the cover, ect. While you've got the cover off it would not be a bad idea to have the timing chain inspected for stretching/wear as you should be doing that after about 100k (they do stretch/wear over time and that means new chain, guides, gears, ect. but usually that's in the 200k~300k+ range)
Its on the more expensive side for a timing chain reseal (It is dealer pricing after all), but be glad you don't have a 2GR-FE (3.5L V6) transverse engine where the entire engine has to be dropped to do the job (even more labor.) This is the inherited cost of a timing chain motor, longer service intervals for some components, but very expensive in labor and cost when they do wear out.
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Post Note-
Switching over to a 2UZ-FE (4.7L V8) will be a bit more difficult as you will need an ECM as well as an immobilizer module (I don't know if you can seed a 1GR-FE (4.0L V6) Immobilizer for a 2UZ-FE ECM, depends on how lenient Toyota was in that department), the 4WD module may not like the 2UZ-FE module also (I haven't heard anyone try and put the Part-Time 4WD set-up in a V8 so I can't say how well it'd work), as well as some of the other associated components (these are more bits and parts like having new mounts made if needed, hoses, fittings, wiring, ect.) In the end while the motor would be about $2500, the ancillary costs would make the swap expensive. Conversely if you're swapping in another 1GR-FE, you need to make sure its the same year as there is a difference between some years that was never properly explained by Toyota (one member mentioned newer 1GR-FE's in the 4th Gens had a 3 wire Camshaft Position sensor and different VVTi assemblies and this caused an issue with getting the engine to run right for him.)
