Double Back.
Civil HUDs are not cheap; flight operations are significantly different from military use.
HUD certification can be just as expensive as a fully capable AP, and then involve additional training costs, and currency requirements.
A previous comment that the accident operator traded AP servicing cost for HUD use, appears to show how easy it is to misjudge relative cost and safety.
Other issues relating to HUD operations are discussed in
Use of HUD for visual approach and landings