You didn't say what your starter instrument is.
How much depends on how much you want to spend I think. Example: You can get an Ohana with a solid top, that properly setup will meet your requirements, for $115.
There are even sub $100 ukes I'm sure that have as good as intonation as more expensive, so long at they were built to proper specs and setup correctly. It's more hit and miss with the lower priced stuff though, obviously.
I have a $115 Ohana SK-20 in my possession right now that is a great player. It sounds good too.
Of course if you have the money and want to spend on an even nicer uke, that's an option too. I'm just saying you don't have to spend a lot to get a decent instrument these days.
As mentioned above, do make sure you get it from someone reputable who includes a setup before shipping the instrument. Higher priced instruments sometimes have issues too, so this is very important.
There is no such thing as perfect intonation with any stringed instrument. I know some are better than others though, for sure. The shorter the scale length, the harder it is to get the intonation right. Then strings and player technique come into play as well. If you want the best possible intonation you can achieve, the uke will have to be setup for one particular string set and then you'll have to stick with that particular set in the future when you buy new strings. There isn't much different between some sets, but strings can make a difference.