Although I own an Ace 250, and love using it, I personally think it is well over priced here in Australia. There are more feature packed starter detectors out there that come in at a lower price than the Ace, including the Teknetics Eurotek Pro ($259), and the Teknetics Delta 4000 ($330) - the Euroek Pro can be optioned with the large 11" DD coil which is still $30 less than the standard Ace250.
The delta looks like an attractive starter detector with more fearures that the Ace, despite being cheaper, including true all metal mode for more depth capability, both 1/4" & 1/8" headphone jacks, volume control, numeric target ID, fast recovery time over targets, and a running depth display. There are also a plethora of aftermarket coils available from NEL to suit the greek series detectors.
The Eurotek Pro does not have an all-metal mode, but you can use the pinpoint button for scanning the ground, much as you would with the Ace. Other unique features on this detector are the iron volume control, iron indicator screen icon, numeric target ID, and Vbreak tones as on the G2/Goldbug Pro (VCO tone over high conductors). This detector was made to cope with iron infested sites.
Both detectors run 7.8kHz, which is slightly higher frequency than the Ace.
Teknetics are a part of 1st Texas detectors, who also produce Fisher and Bounty Hunter detectors.