Free is not quite right, brother. Yes, some years, the US gave funds to Egypt that covered its buys …
so that in the end it was virtually free. There is a cost however.
The US Foreign policy acts on FMS ( +- "free" ) sales. At times, it favors a slant : Cold War = sales to anyone openly anti-communist. At times it favors an ideology : Carter or Obama opposing sales to "bad" human rights countries ( dictators or coup makers as in President al-Sisi takeover dispute ).
Egypt F-16 Peace Vector
At all times, the USA keeps a potential option ( assistance or technology based ) to limit the use of these weapons.
France always sells, albeit with financial assistance and training to friends, its weapons. That makes these pricier but in exchange, the only holdback is through parts and maintenance. Once the weapons are acquired, the only real technological holdback applies to war against the customer.
Example : Egypt has F-16s and now Rafales.
When it wants to use the Falcons, Washington may lock systems on a case by case basis, making their use difficult if not impossible ( say to bomb Israel if things went bad … or Libya last year? ).
When it will want to use the Raffys, Paris will only disable the systems if Egypt is facing France in a war. Any other case is your choice to make.
The difference in this more or less covers the difference in price.
It is for each buyer to decide if its context warrants one or the other.
When 100% aligned with America, FMS sales are very interesting. The only drawback to that paradigm is that changes in viewpoint from Washington can vary over 4 years ( a Presidential term ).
When more autonomous, buying from the more autonomous seller fits better.
In all honesty, Russia is on average closer to French ways and less regarding.
I hope this helps, Tay.