For Mexicans citizens to buy a home in the El Paso with cash is not only possible, it is easy. You will need to provide proof of funds and an ID, generally a tourist visa B1/B2. In addition to the cost of the home, you will also be expected to pay closing costs, which will be approximately 2% of the sales price. You will need to have a proper contract prepared, sales price and terms negotiated, and an El Paso reputable title company hired. You can do it remotely. It is just a matter of signing and faxing the documents. A good real estate agent from El Paso will be invaluable in guiding you through the process.
If you need a loan: This can be tricky, because, in addition to proving who you are, you'll need to prove income and credit, just as any US citizen. The problem is that US banks in El Paso usually have difficulty accepting foreign credit bureaus, proving income, taxes, time on the job, etc. Three other possible options. 1st, can your friends in El Paso qualify without you, you could be added to the ownership after the home is purchased. 2nd, many times it's easier to get financing in your current country. 3rd, a hard money loan, interest rates are higher and you'll need 40%-50% down, but no credit or income documentation is necessary.
To avoid any oversights on issues so important talking with an El Paso immigration attorney is highly recommended in the clarification in advance regarding purchase and sale. Tax implications regarding sales to foreigners is an issue that needs to be addressed and understood and not come later as a nasty surprise. When a non-US citizen decides to sell their US property in El Paso, certain tax restrictions may apply. FIRPTA, the Foreign Investment in Real Property Tax Act, was enacted in 1980 and provides that if the Seller of real property is a foreign person, the Buyer must withhold a tax equal to 10% of the gross purchase price unless an exemption applies. A foreign person is a nonresident alien individual; a foreign corporation not treated as a domestic corporation; or a foreign partnership, trust or estate. A resident alien is not considered a foreign person under FIRPTA.