First, I hope you can sort out a payment type plan so that Blue can be tended; best of luck in that regard. I'll be thinking of Blue.
About the urine, I have 3 cats and after alot of following them when they went to the box, I learned who did what and where in the LB. Without fail, I know exactly what deposits are from my civvie, and by location, I can tell which was from the other two. I always use clumping litter as well so that I can track volumes.
It is so hard to see those high numbers; it really hurts to see them but let's hope that you start to see Kasha feeling a bit better and perk up some. The numbers will come down after you start to see those improvements.
Don't forget that the shed needs to top up when you give the increase, so it may take up to 6 shots before Kasha gets the benefits completely. Hopefully, you will see better numbers sooner than that, but hang in there, Kasha will come around.
For the dental, it all depends on what needs to be done. All vets are different, and if there are no extractions or other extras, then the amount could be lower. The dental can make a HUGE difference. After Shadoe had her dental and had just one bad molar pulled, she really started to improve. Ask if the teeth can be checked, cleaned and maybe Xray any that look bad. Then you can decide what additional can be done.
Shadoe's total was $629 with 1 extraction, 4 Xrays-before&after for the extracted one, and all the goodies like fluids and pain meds and stuff to take home like the A/B and pain gel that went with it. I can list all the items included like nerve block and transdermal gel if it will help you; just let me know. That's in Canada though.
Lots of pats and scratches for all 3 of your kitties