Where are you north or south and what town for a better answer
chip! what on earth? our king size was about 25-30k pesos (can't remember) and i thought i was a good price. 5k pesos for a mattress? is it a slab of sponge sewed inside few old t-shirts?
so, in other words: used and refurbished?
i did mention you can get something at any price, really. but i'll take new, thanks.
I have bought a king-size, pillow top, back in 2007 for around 14.000 pesos, new. It's still serving its duty.
In March we bought bunk beds for our grandsons, full on bottom, twin on top. We bought the mattresses at the same place [in Palenque, south coast] - got a gorgeous, comfy, pillow-top full size mattress for about 8,000 pesos, I think the twin was about 3000, not pillow top [for top bunk, rail not that high, with pillow top the kid could fall right off].
At the same time we bought those, La Sirena was running a 20-25% off sale on all name brands [Sealy, etc], so check there too, they had some nice mattresses.
Those are pretty good prices, too bad Im in NY and can't check La Sirena.
pricesmart also has mattresses. and plaza lama. check the big stores first.