Do not buy ergos on eBay A LOT are fakes,also a lot of 'ergo' websites are fake.
'love to be natural' are trusted sellers-they sell lots of other lovely slings too!
My first was a hug-a-bub but there are mobys,VictoriaSlingLady,etc all the same sort of thing.
all good,and all under £50.
Ergos are fantastic if you want buckles,as are wompats and beco's.but are more expencive.
Then there are woven wraps,similar to 'strectchys' but made with woven fabric,you can carry heavier weights with these (I can still carry my 4yr old comfortably!) try Lenny lamb,for a good,but cheap,make.
And finally Mei Tai's (similar to a buckled carier but you tie with knots rather than clips) a good starter make would be a hop-tai.
I hope that was useful and not to confusing!
The most important things are to use a certified,tested,carrier.
Make sure your baby is Close Enough To Kiss the top of their head.
that their legs are supported Knee to Knee,and their bottom is lower than their knees (like they are squatting! This is important for hip development)