The Crosman Quest is a decent cheap .22 spring air rifle for about $100 on sale. It shoots pellets at 800 fps. It does have some recoil but at least it works. And there's plenty of pre-compressed air and CO2 models that once set up will last a lifetime. I have storage tanks and guns that use both.
The better pre-charged target rifles and pistols will outshoot most rimfires and won't break the bank. As a matter of fact, they require more trigger discipline since they promote the Oympic sporting events that some of them are designed to compete in.
And if it is repeaters that you want, then those models are available too.
Shooting powders in the house is not ideal.
I try hard to contain just the pellet lead spatter by covering up the bullet trap and shooting into a small hole.
If you don't want to pay for Colibri's but would rather invest in a .223, then you're missing out on what it is that air guns can teach.
The precision shooting techniques, skills & methods are transferable between guns to a greater extent than even reloaded primer ammo can accomplish when compared to shooting the same centerfire gun.
Why? Because recoil is taken out the equation when a shooting a CF with just a primer and pellet. Plus the accuracy won't be there and it will still only be a single shot.
Meanwhile there's air guns that are repeaters that come in tons of configurations that are actually made to shoot the pellets accurately and safely without needing to shoot off primers indoors.
They even make air guns in centerfire calibers!
Lewis & Clark took hard hitting repeating air rifles that shot round balls all the way to the Pacific! There's a series of articles all about antique airguns on the Beeman website.
Good luck, I really do admire your persistence.