Realtor typically charges 5% of the sale price.
Attorney charges 5-10k pesos depending on complexity of the sale and how many times they have to go to II. This is just for the actos de ventas, title research, traspaso etc. If you have a good attorney, the tax is where you will save money. The tax charged is 3% of the total value of the land/home, PLUS 12% of the 3% , it's an odd scale but that's how it works.
Ok, the way you save money is 2 acto de ventas are done, one is done with the real selling price, let's say 5,000,000 for example, and the other is done using the valuation that impuestos internos has on the property. Many times with the right attorney the valuation can be a fraction of the value. One example is I bought a plot of land for 1.23 million pesos and was charged tax on 223,000 since that was 10% above what impuestos internos had the land valued at.
With all that said, never trust attorneys.. they are always looking for ways to squeeze a little more, even when they are your loving aunt.. lol hi maria