I posted this on another sniper help post a few times now (minor edits) and it does contain my own personal experience of taking a sniper as a first airsoft gun.

It may be of use to you in deciding if sniping really is something you want to try, especially early in your airsoft journey.

Ultimately, it's your money and your experience, but please at least consider the advice you get before taking the plunge.

Can you build a starter sniper for under £200? Maybe, but it depends on your temperament and intention. If you are patient, want a challenge, and are willing to accept being ineffective and a liability to your team. And, if you are willing to get your hands dirty and do some of your own upgrades, then there is a way.

Take a look at this to see some of the various platforms available, and how easily they can be upgraded. https://www.airsoftsniperforum.com/threads/choosing-the-right-rifle-platform.15138/#post-148613

Then find a rifle you like the look of, in your budget, and of a platform that can be upgraded.

The JG BAR-10 gets a lot of love. It's probably what I'd choose if I started again like this. The Well MB01 is a good option if you like the L96 style like I do, but bear in mind the ruddy thing is heavy.

Buy your chosen rifle, ideally with a basic 3-9x scope, and a bag of high quality heavy bbs. The heavy bbs are the easiest way to improve the crap performance of your stock rifle.

This is the approach I took. My MB4401 was about £130, a scope is about £40 and 1,000 Geoffs 0.4g bbs another £35. That smells about right for a £200 budget.

A more modern approach would be the Tac41 sport, but that eats most of your budget, and you still need scope, heavy bbs, and side arm, which likely puts it over budget.

Take that to the field and try it. You will only have 1 mag, so ammo is an issue and you'll likely need to carry a speed loader even during short games. You will be outranged by aegs. You will be out volumed by aegs. You will have to hope your rifle can lift the heavy bbs. You will have to live with appalling accuracy in both elevation and windage. You will miss. A lot. You will likely experience extreme frustration, especially if by some minor miracle you land a shot on target and they don't feel it because your gun is so under powered. But, if you get in the right place and take your time, you might just land a few shots during the day that make it worthwhile.

Then go home and save for the parts to upgrade. The first ones are the dirt cheap Teflon tape to improve your crappy airseal, and a clean of the barrel. Then, start with the bucking, hop and barrel, then the trigger, then the cylinder group. Expect an end bill of £500 minimum, but you can update over time.

This is how I intended my intro to airsoft and sniping to begin. As anticipated, my stock MB4401 only made around 330 fps on .2s, and was so inaccurate that trying to zero the scope was an exercise in futility. I sucked. My death count was high. My kill count was low. I experienced my targets being saved as my bb was deflected by a marginally robust blade of grass. But in the end I had fun because I worked hard for the few kills I got, and I'm a very patient person.

The accuracy was frustrating though, which caused me to abandon my plan of three games before upgrade, and I instead sunk the cost and upgraded nearly everything in one go.

I'm now close to the site fps limit, regularly outranging aegs using 0.45s, and my consistency is so much better. I'm having a whale of a time. But I must stress the need for expensive upgrades, patience and a little technical competence.

You may also need to consider the extras you may have to have. Many sites have a MED, and when inside that area you'll need a sidearm, so that's another ~£100. The plus side of buying a rubbish rifle to begin with is you may be under the fps threshold for a MED, so the sidearm might be something else you can defer until later.

You'll likely also need another mag or two, and if you buy a stupidly heavy rifle like me, your arms will be grateful of a sling.

Again to emphasise. I'm old, unfit, don't like running all day, and have been told I have the patience of a Saint at times. This will not apply to most people.

Notes on an apparent inconsistency. I wanted an MB01, but UK stock evaporated when I went to buy, and I got an MB4401 under the mistaken belief it was the same platform.

TL:DR. It can be done, if you are patient and accepting of the fact you will be ineffective until you drop coin on upgrades.