What is a lotus mat? Is that a brand?
There are so many brands and types of mat, some very affordable, and some super expensive.
It will be a case or trial and error to get a mat that suits you- but if you are new to yoga I wouldn't spend too much to start with.
Even buying a mat in a supermarket is totally fine- and you will want one early on in your practice- many gyms have communal mats, but are often grubby, and yoga sometimes involves having your face to the floor.
Some people like thick mats - they do provide cushioning for knees etc, but are not that great for balance- they are a little wobbly making! But you can step off onto the floor for balance poses.
You can also double up your mat for positions that require weight on knees, or use a second mat or pad./
Some mats do stretch quite a bit or slip and can make warrior or down dog positions less stable. Part of yoga is about confidence and learning to navigate that line- it isn't helped if your feet feel insecure. Some mats will stretch and start to sag and become floppy with age.
I have a few mats, but overall mats are secondary to practice. I will practice on bare wood, grass, carpet, a blanket, wherever I happen to be.
My current best mat is a rubber one, cost around £85, and it is good.
Not without limitations though. It is quite heavy, so if you need to walk far or use public transport that may be an issue. It was also quite smelly to begin with- being made of natural rubber- but the smell goes after a couple of months.
It is thin, and not much padding- not an issue for me, but I know some yogis need some extra cushioning. But the benefits are amazing grip, I stick like a gecko to the mat, it has allowed me to deepen my practice, secure in the knowledge I am unlikely to slip. It doesn't stretch either, so once my feet are anchored they are firm. My may also has a simple symmetrical design ( a tree) which helps me align my feet.
So although expensive my rubber mat is the best for me- but it really is a minefield out there, and I am sure there are materials and designs that are great, but I know nothing about.
Sorry for rambling on- but in short I would say spend little and work our what your own requirements are, the if you do need to change mats you haven't wasted too much money.9