Birdys start at over £2000 for the original design but the current monocoque design.
Terns are not as compact but could be better. Not if you're tall though. Above 6'3" and despite tern claiming they're good to 6'5" tall they're not, that's from one of the biggest folding bike retailers and tern main stockists in the UK. I asked them and under their 30 day no quibble refund scheme they know they will get tern bikes back if the purchaser is tall. They only sell brompton bikes if your close to 6'3" or above. I'm in that taller bracket.
Airnimal you need to take the wheel off and it's got a larger fold size.
Bike Friday make good range of folders and their world traveller is a reasonable fold size and effectively custom built for the rider not making one size fit all. Costs £2500++. Great bikes though.
IIRC is the 3sixty bike out of Singapore I think that is a direct copy of Brompton fold. I think aluminium alloy frame but I might be mistaken in that. Cheaper than bromptons if you can get that 3sixty bike sent here of course.
Brompton comes up for sale their site every week now for a few months. Not many and they sell quickly. Mostly electric and superlights but there's been plenty of m6r or M6L with battery or dynamo lighting. Mostly in black only but you get the odd reds too.
Near me there's one shop with a nice red in the window and more in stock apparently. A further away retailer, smaller shop with only one outlet, had one a few weeks back too. They've been told by their brompton rep they'd be able to place orders for only a few brompton bikes then nothing for some time. She was angry with the way brompton was dealing with small retailers even though they actually sold quite a few annually for years.
For my multi modal commute I have very little choice. I can just about afford the £1300 or so but not £2700 for a Birdy or £3600 or so for a hummingbird. BTW if you would rather buy a hummingbird for commuting then I wonder how much weight if you were able to add in guards, means to carry luggage, lighting options, etc. Bromptons come with most of those in one model or another so I suspect it's not completely a fair comparison. However even stripped down Brompton sounds be a lot heavier than the hummingbird but probably more durable for commuting use. Is the hummingbird even meant as a commuter?
I really don't want to buy a brompton for it's many flaws but I suspect my impending move will mean I need a solution which it seems brompton is unfortunately the only option left to me.
BTW you can't say the s bar is the perfect option for everyone because it depends on your height. There's a good graph I've seen on a YouTube channel for touring with folders that plots a line for each bar type in a graph with inseam in the X axis and height above or below the level of the seat. You need to check that out if you're thinking of buying a brompton. For my size the s bar would be between 10 and 15cm below the seat. The m bar is 5cm below, which would be my preference. H bar is over 5cm higher.
The whole bike sector is a mess right now for many reasons. Some EU based retailers and bike brands don't even ship here after brexit. Shops are all low in stock. I think you just have to buy the bike you can get that will do what n you want not your ideal bike. That means different specs and colours you might not actually like. Bromptons you have to get what you can not what you want.