We have covered this topic before and explained the long term cost of buying cheap, but it seems that buyers still want to pay as little as possible for office chairs.
At best this is just a false economy, and at worse could cause you a lot of pain and even long terms back problems.

We are not designed to sit in the same position of long periods of time, so office furniture manufacturers spend a lot of money on specialists and ergonomists to make sure that their seating is designed top be as supportive and as comfortable as possible. These costs have to be added to their manufacturing costs.
Also, it goes without saying that better quality mechanisms, and more adjustment features cost more money.

The office chair market is huge, and quality and prices vary enormously.  Buyers frequently decide on their purchase just by looking at a picture in a catalogue or on the internet. As they are unable to verify the quality of the chair, they use price as their comparator, which is a big mistake.

There are many  cheaply designed, poor quality chairs which are definitely not suitable for long term use.  Inferior steel and poor quality welds are synonymous with far eastern manufacturers and can be clearly seen in office chairs from these areas.
The designs are basic and are usually copies of what we used to sit on 20 years ago. The manufacturers main aim is not to provide you with comfortable, good value seating, but purely to make a profit.
They may be making chairs now, but next year might be making walking frames ( which might actually be useful if you have been using their chair for a year), so after sales service will always be a problem, in as much as there won’t be one.

So you really need to think about your office chair budget in the same way as a mattress for your bed.  Most people understand a mattress has to support you properly for many hours a day (night) and for many years, so they realise that they need to spend as much as they can on this product, to get the best from it.
An £80 mattress is still a mattress but would you really want to sleep on it every night for a number of years. That’s 7p a night for a bad nights sleep and backache.

The same applies to your chair. £100 for an office chair which is guaranteed for 5 years, and  will probably last for 8, works out at 3p per day.

Is your comfort and more importantly your health worth so little.

Most UK chair manufacturers are in the business as professionals, and only make office chairs.
They want their customers ( through their dealers) to be happy and to return to them when their chair needs replacing. They can offer continuity on their ranges, and provide a full after sales service.
They often have showrooms where their whole range can be seen and tried, and can often supply sample chairs for a few days.
And yes, this does cost more,- about 4p a day more, so speak to your office furniture dealer now