I've been doing seat checks for almost 2 years and the number 1 question I am asked is, "When can I turn my child forward facing?"
Proud parents are so eager to see their baby meet milestones that they don't realize the implications of doing so: turning your baby from rear-facing to forward-facing is a step down in safety.
We'd all be safer if we could ride backward (maybe one day we all will thanks to Google's driverless cars!), but it's even more beneficial to let your child remain as such until they no longer fit in their rear-facing seat. The reason for this is due to their flexibility; a toddler’s vertebrae are connected via cartilage rather than ossified bone, like yours and mine. The average 2 year old's spine has not yet started this hardening process, so crash forces can be devastating to their little bodies when they are facing the front of the vehicle.
So. Rear-facing is safer. Got it. (Read more here if you're so inclined.)
When my kids were newbies there weren't a lot of options to work with. I managed to keep my daughter rear-facing until she was nearly 3.5 years old in a Graco MyRide, and today my nearly 4 year old son is rocking the rear-facing Diono Radian RXT.
Nowadays it's a totally different story! Rear-facing options up to 50lbs and a full 49" or more?! To be honest I'm a little jealous of all the options you have, but don't worry, I won't hold it against you. There are extended rear-facing options for every budget, with seats ranging from $180 to $500. These seats are often on sale, too; I recently saw a Graco Extend2Fit for $130! My 23rd percentile 8 year old fits - comfortably rear-facing - in one of those bad boys!
Why the huge price range? All car seats have to pass the same standards set by the government, so it's impossible to say that one seat is safer than another. When you buy a car seat you're also paying for bonus stuff, like improved ease of installation features, moisture wicking fabrics, steel frames, and anti-rebound technology (just to name a few).
Don't worry if you can't afford an expensive seat. Car seats are life saving devices that we hope to never need, but they must be used correctly every single ride - and the safest seat is the one that fits your child, your vehicle, and your budget.