Want to vs One two

Solution 1:

Many people do not have the same vowel sound in want and one.

In British English, want has the LOT wowel (/wɒnt/), whereas one usually has the BUD vowel (/wʌn/). However, the pronunciation of one as /wɒn/ does exist and is gaining ground. It makes one a homophone of wan.

J. C. Wells, whose phonetic notation I use, has some statistical information in his Longman Pronunciation Dictionary taken from the surveys he conducted. He gives the distribution of both pronunciations as:

/wʌn/ 70% but above 80% among older speakers, /wɒn/ 30% but above 40% among younger speakers.

Now to American English and want. The most usual pronunciation of want, according to Wells' LPD, is /wɑ:nt/ with the FATHER vowel, less common are /wɔ:nt/ with the WAR vowel and /wʌnt/ with the BUD vowel. So there is a case for homophony between want to and one two in American English too.

However, in "normal" speech in both varieties, want to is often reduced to wanna (no t sounded), and to to /tə/, whereas two will keep its full, non-reduced sound /tu:/.

To conclude, the chances are want to and one two won't be pronounced in the same way, at least in the two varieties of English I've described.