Washington is 25% more expensive than Allen.
When comparing Washington, DC and Allen, TX, the overall cost of living indices are 171 and 137 respectively (national median = 100). Rent is comparable in both cities, with less than $50/month separating them.
Median household income is $22,843/year higher in Allen. Home values also differ significantly — the median in Washington is $724,600 compared to $429,900 in Allen.
Texas has no state income tax, giving Allen residents a significant tax advantage over District of Columbia's 10.75% rate.
Washington vs Allen — common questions
Other cost of living comparisons for Washington and Allen