There is some age old advice that suggests you buy the best you can afford ... the range of tools available is vast, to suit all pockets. At the quality end, you have professional standard tools like the Bahco range just mentioned (Felco are a serious competitor, but I won't be drawn on comparisons). Then you have general DIY quality tools which you are likely to find at your garden centre (possibly overpriced) and finally your premium range, at low cost outlets such as the discount stores and places like Poundland. Professional standard tools are a delight to use, they are designed for the demands of diligent craftsmenpersons, and are likely to embody subtle features to aid enhanced use. An example is the Bahco secateurs, which come as standard with a range of springs, selectable according to your usage. The other feature you will get with the professional standard is quality materials, the steels used for the cutting edges will be first class, and hold sharp edges for extended periods of time.
The DIY standard, mostly bought from outlets such as B&Q, are suitable for most 'amateur' gardener's requirements, and possibly represent the best compromise of quality and cost.
The third category is the premium range, which requires caution, as the quality can be dubious, and can result in unpleasant accidents.
I own tools in all three ranges, but I consider I am able to use the tools within their limitations, and I always garden with adequate PPE (personal protective equipment - safety glasses and boots). The last grouping is reserved to a couple of pairs of cheap secateurs to be left lying around (Poundland - used purely for rough jobs, hedging etc) and kneepads, which actually work well (sorry Alishka ... ).
What you should be aware of though, it is possible to do a bad job with good tools, or a good job with bad tools, but the latter is far more difficult, sometimes impossible.
I hope this has helped, rather than hindered or confused you.
